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Gunner unaware of hospitalised teen inmate

The Northern Territory's chief minister admits he wasn't aware a boy was hospitalised after Don Dale Detention Centre guards violently wrestled him to the ground last December.

CCTV camera footage taken three months ago was tendered to the juvenile justice royal commission on Thursday, showing an inmate being tackled and stripped by two guards as three other officers watched.

Michael Gunner said he was never briefed as the matter wasn't pursued after the teen's lawyers, the Children's Commissioner and the department responsible for youth corrections examined the footage.

"The complaint was dropped," he said.

"There's always going to be moments of tension at youth justice facilities ... that's why you want to have independent scrutiny."

While Mr Gunner said the commission must make broad recommendations, he questioned its ability to make detailed findings about what happened behind bars.

Lawyers for the government have vented frustration that the inquiry is preventing them from cross examining controversial abuse claims from current and former inmates.

"Our concerns would be if they try to make court level findings when they haven't gone through the same scrutiny or evidence testing as they would in a court."

The youth, identified as BH, said he was pacing around an internal courtyard, upset and crying, when two guards approached him in December 2016.

CCTV footage shows the boy then try to push one officer away before they both grab the youngster.

"The next thing I remember, I was being forced down onto the concrete floor. I blacked out," BH said.

"When I came to, the guards were on my back holding me down, pushing my face into the concrete.

"I wasn't resisting and they kept pushing me back down. I was swearing because I was in a big mob of pain."

Vomiting and with blurred vision, BH was taken to hospital in an ambulance.

He was taken back to Don Dale later that night where he was put into a high security unit cell with no fan, a blocked toilet and little ventilation, he said.

"I remember sweating all night and not being able to sleep," BH said.

"I got really thirsty and had a headache. I didn't bother asking for more water as I knew it was a lockdown and they wouldn't open the hatch."

It was the same day former inmate Dylan Voller, who was tear-gassed, shackled and put in a spit-hood in August 2014, was giving evidence to the commission in Darwin.

One month after the gassing, the head of the professional standards unit David Ferguson published a scathing report into operational failures at Don Dale.

Appearing before the inquiry, Mr Ferguson said most of the recent assaults and escapes were "entirely preventable".

"It should be obvious to anyone that if you treat youths like animals by not communicating, threatening, belittling them, withholding food and other entitlements, they will react in an aggressive way," Mr Ferguson wrote.

The report detailed inmate overcrowding and increased lockdowns, along with dismal training, staff shortages, drug dealing and a culture of bullying.

It referred to a "boys club" mentality among certain guards involved in martial arts fighting who flouted rules with impunity, teasing detainees and assuming the "enforcer role".